threadpool: fix a race condition during downsizing #4129
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kleisauke
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Aug 29, 2024
Under certain conditions, particularly with short-lived pipelines and high thread concurrency, a race condition could occur between decrementing and restoring the `exit` flag atomically, potentially causing more threads to cooperatively exit than intended. Fix this race by using a single atomic compare-and-exchange, which only resets the flag when it is set. Additionally, the flag's type has been changed from `int` to `gboolean` for clarity.
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Upon a closer look, I don't think this is a race condition. The timing of the exit count increment in I do like the |
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Good idea, let's make this a polish on master instead. |
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Great! Closing in favor of PR #4123. |
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Under certain conditions, particularly with short-lived pipelines and high thread concurrency, a race condition could occur between decrementing and restoring the
exitflag atomically, potentially causing more threads to cooperatively exit than intended.Fix this race by using a single atomic compare-and-exchange, which only resets the flag when it is set. Additionally, the flag's type has been changed from
inttogbooleanfor clarity.Context: #4069.